Hay, which is extensively used by farmers for fodder is prepared by mowing and raking grass or leafy plants in windrows which remain in the field for a few days to dry before being picked up and compacted for storage. To accelerate the curing of the hay, it is a common procedure to turn the windrow with a side rake once the upper side is dry, to expose to the sun the underside which is still damp.
In the past, various machines have been designed to automatically carry out this operation. As an example, the U.S. Pat. No. 2,391,427 of J. B. Kucera, discloses a windrow inverting apparatus in the form of a carriage to be drawn by a tractor and comprising a lower horizontal platform with inlet and outlet openings, and an upper horizontal rotatable device with downwardly extending prongs. In operation, material from the windrow enters on the lower platform through the inlet opening and it is advanced to the outlet opening by the prongs of the upper rotating device. From the outlet opening the material falls on the ground in inverted condition.
While these types of devices are satisfactory for certain types of grasses, when used to turn a windrow of leafy plants such as alfalfa, clover, trefoil or the like a loss of the nutrient qualities of the hay has been noted.
Most of the nutrition of the hay made of leafy plants is contained in the small leaves thereof which dry faster than the stems do and become brittle. The windrow turning apparatuses of the type described above manipulate the hay vigorously by advancing the hay by means of prongs engaging the upper side thereof which is dry. As a result, many leaves are detached from the stems, severely degrading the nutrient qualities of the hay.